JP3175779U - Exhaust valve rod for diesel engines, etc. - Google Patents

Abstract

Disclosed is an exhaust valve rod for a diesel engine or the like that is inexpensive and can improve durability of an expensive exhaust valve rod such as a marine diesel engine.
An exhaust valve rod 1 for a diesel engine or the like, which uses heat-resistant steel of a valve material including SUH1, 3, 4, SUH31, Nimonic 80, 81, which is generally used as a base material of the exhaust valve rod 1. Then, the contact surface 3 is overlay welded with an Inconel high-temperature corrosion-resistant Ni-base metal that does not contain a P (phosphorus) component in the base surface layer, and Ni 40-60%, Cr 60-40 on the surface layer. The super-alloy of the superalloy of which the main component is% is overlay welded, and the overlay metal is diluted to form overlay welding, and P ( The Inconel high-temperature corrosion-resistant Ni-based metal that does not contain the phosphorus component is overlay welded, and the high-temperature, high-hardness corrosion-resistant Ni-based special metal of UD520 is overlay welded to the surface layer. A metal is diluted and formed by welding.
[Selection] Figure 1

Description

  The present invention relates to exhaust valve rods for various diesel engines of ships.

  Conventionally, various kinds of martensitic heat-resistant steels SUH1, 3, 4 or austenitic heat-resistant steels SUH31, 37, SNCrW are used as exhaust valve rods for various diesel engines and gasoline engines of ships. Coal stellite or Ni-based metal plating such as colmonoy is used on the sheet surface.

  The exhaust valve rod is the most important and expensive component in diesel engines and gasoline engines, and the weight of the exhaust valve rod in the shipowner's economy is quite large. Thus, attempts have been made to extend the life of the exhaust valve rod so far.

  In the past, in the actual machine test that increased the high temperature strength of the sintered stellite valve seat, the seat surface was healthy and without any indentation even after 16,000 hours, and the exhaust valve stem was used for the seat surface. If the high-temperature strength is higher than a certain value, it was considered that the maintenance time and the life of the valve can be made longer than the current situation.

  In addition, from 20 years ago, as disclosed in Japanese Patent Laid-Open No. 5-22475, an exhaust valve rod made of Ni-based heat-resistant steel Nimonic (Nimonic (registered trademark) 80A) material has been used. This valve material has better heat and corrosion resistance than the above metal material, has a long service life, and is currently stable in quality in large diesel engines.

  In addition, most of the high temperature corrosion of the valve umbrella contact surface common to the exhaust valve stem is first carburized by the high temperature and high pressure exhaust gas, which reacts with the chrome of the chemical component of the exhaust valve body and reacts with chrome carbide. It was thought that it was formed at the grain boundaries and caused carburizing pitting.

  Around 1984, when repairing the exhaust valve seat of the forged product Nimonic80A, the welding material of the same kind (Nimonic80A) was used, and the surface of the weld was peened and the surface of the welded part was peened to increase the hardness. By using age-hardening heat treatment and increasing the hardness at high temperature, the service life was considerably extended.

  On the other hand, the temperature of the exhaust valve umbrella surface during engine operation is recorded at 600 ° C. or higher and 100 ° C. or higher at 100% load of the 880BHP / cyl engine. Considering the recent fuel oil properties, in addition to the above phenomenon, it is necessary to provide an exhaust valve rod excellent in high-temperature corrosion resistance such as sulfur attack resistance and vanadium attack resistance.

  Thus, in order to achieve a long life of the exhaust valve rod, 1) the metal of the exhaust valve seat is a material that can obtain high hardness at high temperatures, and 2) the metal on the flaming surface side is in a high-temperature high-pressure corrosive atmosphere 3) Exhaust valve base metal that is based on metallic Fe is an intermetallic compound in the precipitated eutectic of the metals that constitute 1) and 2). If Fe is included, a brittle compound may not be formed if Fe-based, so the edges must be cut with Ni.

  Further, marine low-speed diesel engines use poor fuel, and parts around the combustion chamber are exposed to harsh conditions. Among them, exhaust valve stems are most severe. The maintenance of the exhaust valve rod must stop the engine and release the exhaust valve rod, and this maintenance interval is currently estimated at 10,000 hours. However, engine manufacturers and customers are planning to cut costs with the goal of over 50, OOOHr in the near future.

  Further, in the past, when looking at troubles in the exhaust valve rod and solutions, most of them are troubles caused by gas blow-out from the seat surface and high-temperature corrosion of the contact surface.

  The cause of this is that there are many aspects resulting from the use of poor heavy oil, and the most effective countermeasures are to increase the high-temperature hardness of the seat surface material, and the exhaust valve stem with a material that stops high-temperature corrosion on the contact surface. Is to make.

  However, since the above materials are very expensive, when manufacturing an exhaust valve stem, a conventionally used class of material is coated with a long-life type high-quality material to comprehensively have a long life. The challenge was to make an inexpensive exhaust valve rod and make it maintenance-free.

  The present invention has been made in view of the above points, and in order to solve the above-described problems, the present invention is an exhaust valve rod for a diesel engine or the like, which is generally used for a base material of the exhaust valve rod. 4, heat resistant steel of valve material including SUH31, Nimonic 80, 81, and the contact surface of Inconel (Inconel (registered trademark) the same below) containing no P (phosphorus) component in the base layer Overlay welding high temperature corrosion resistance Ni-base metal, overlay welding the high temperature corrosion resistance Ni base metal of the superalloy mainly composed of Ni 40-60% and Cr 60-40% on the surface layer, these It is to provide an exhaust valve rod for a diesel engine or the like, characterized in that the overlay metal is diluted and formed by overlay welding.

  In addition, an Inconel high-temperature corrosion-resistant Ni-based metal containing no P (phosphorus) component is overlay welded to the seat surface of the exhaust valve rod, and the high-temperature, high-hardness corrosion resistance of UD520 is applied to the surface layer. The present invention is to provide an exhaust valve rod for a diesel engine or the like according to claim 1, wherein a weldable Ni-based special metal is welded and the weld metal is diluted and welded.

  Further, an exhaust valve rod using heat-resistant steel of valve materials including SUH1, 3, 4, SUH31, Nimonic 80, 81 generally used as a base material for exhaust valve rods of diesel engines, etc. The base surface layer is overlay welded with stainless steel metal for heat resistance including SUS309, 310, 316, and the intermediate surface layer is overlayed with Inconel's high temperature corrosion resistance Ni-base metal that does not contain P (phosphorus) component. Welding and overlay welding high temperature corrosion resistance Ni-base metal of superalloy mainly composed of Ni 40-60%, Cr 60-40% on the surface layer, and diluting these overlay metals to form a weld The present invention provides an exhaust valve rod for a diesel engine or the like that has been repaired.

  Furthermore, an exhaust valve rod using heat-resistant steel of valve materials including SUH1, 3, 4, SUH31, Nimonic 80, 81, which is generally used for a base material of an exhaust valve rod of a diesel engine, on its seat surface Overlay welding of heat resistant steel metal containing SUS309, 310, 316 to the base layer and overlay welding of Inconel's high temperature corrosion resistance Ni-base metal not containing P (phosphorus) component to the intermediate layer In addition, exhaust gas from a diesel engine or the like characterized in that the surface layer is weld-welded with a high-temperature, high-hardness and corrosion-resistant Ni-based special metal, and the weld metal is diluted and welded to repair. To provide a valve stem.

  Still another object of the present invention is to provide an exhaust valve rod for a diesel engine or the like, wherein the weld overlay is formed by dilution by a submerged arc welding method.

  Still another object of the present invention is to provide an exhaust valve rod for a diesel engine or the like characterized by being subjected to volumeification treatment at 830 to 880 ° C after build-up welding and precipitation hardening at 620 to 680 ° C.

  The present invention is an exhaust valve rod of a diesel engine or the like as claimed in claim 1 of the utility model, and is generally used for a base material of the exhaust valve rod. SUH1, 3, 4, SUH31, Nimonic 80 , 81 is used for the valve material, and the surface of the flame is welded with Inconel's high-temperature corrosion-resistant Ni-base metal that does not contain P (phosphorus) component in its undercoat layer. By overlay welding a high temperature corrosion resistance Ni-based metal of a superalloy mainly composed of Ni 40 to 60% and Cr 60 to 40% to the layer, and diluting these overlay metals to form overlay welding, Uses heat-resistant steel of valve materials such as SUH1, 3, 4, 37, Nimonic 80, 81, etc., which are generally used for the base material of exhaust valve rod, and there is no P (phosphorus) on its flaming surface, Inconel's high resistance to cracking and high temperature corrosion resistance Ni-based metal Exhaust from low-speed diesel engines, etc., which use high-corrosion-resistant durability by combining super-alloy Ni-base metals with excellent high-temperature corrosion resistance such as sulfur attack and vanadium attack, and fueled with crude heavy oil The long life of the valve stem can be expected to be maintained, the maintenance interval can be greatly extended, and the customer's expenses can be reduced.

  Further, according to the present invention, as in claim 2, overlay welding of a high temperature corrosion resistance Ni-based metal of Inconel that does not contain a P (phosphorus) component in the base layer of the exhaust valve rod seat surface, The surface layer was welded and welded with a high temperature, high hardness and corrosion resistant Ni-based special metal of UD520, and the weld metal was diluted and welded to form a weld without P (phosphorus) as described above. The combination of Inconel's high-temperature corrosion-resistant Ni-based metal welding rod with excellent cracking resistance and high-temperature, high-hardness corrosion-resistant UD520 Ni-based special metal, the hardness of the exhaust valve rod seat surface is High hardness can be maintained up to a high temperature range, high temperature-high hardness and corrosion resistance, long life of exhaust valve rods such as low speed diesel engines fueled with crude heavy oil can be maintained, and maintenance intervals are greatly increased Can be extended and contributes to reducing customer expenses It is possible.

  Further, the present invention uses heat resistant steel of valve material including SUH1, 3, 4, SUH31, Nimonic 80, 81, which is generally used as a base material for exhaust valve rods of diesel engines, etc., as in claim 3. An exhaust valve rod having an inconel that does not contain P (phosphorus) component in the intermediate surface layer by overlay welding stainless steel heat resistant steel metal containing SUS309, 310, 316 on the base surface layer on the flaming surface. Overlay welding high temperature corrosion resistance Ni-base metal, overlay welding the high temperature corrosion resistance Ni base metal of the superalloy mainly composed of Ni 40-60% and Cr 60-40% on the surface layer, these It is possible to extend the service life as described above by repairing the contact surface damaged by the use of the exhaust valve rod of a diesel engine by repairing by diluting the overlay metal and repairing it. .

  Further, according to the present invention, as in claim 4, exhaust using heat resistant steel of a valve material including SUH1, 3, 4, SUH31, Nimonic 80, 81 generally used for a base material of an exhaust valve rod of a diesel engine. High temperature resistance of Inconel, which is a valve stem, with a sheet surface of which is welded with a heat-resistant stainless steel metal containing SUS309, 310, 316 on its base surface layer and does not contain P (phosphorus) component on its intermediate surface layer Overlay welding of corrosion-resistant Ni-based metal, and overlay welding the high-temperature, high-hardness, corrosion-resistant Ni-based special metal of UD520 to the surface layer, and diluting these overlay metals to form a weld and repairing Thus, the seat surface damaged by the use of the exhaust valve rod of the diesel engine can be repaired by welding to extend the service life as described above.

  Further, according to the present invention, as described in claim 5, by forming the build-up welding by diluting by the submerged arc welding method, the above-described build-up welded portion is excellent in strength and prevents cracking. It is possible to extend the service life by overlay welding the contact surface damaged by the use of the exhaust valve rod of the diesel engine.

  Further, according to the present invention, as described in claim 6, after the build-up welding, the above-described build-up welded portion is treated at a high temperature and a high temperature by being treated at 830 to 880 ° C. and subjected to precipitation hardening treatment at 620 to 680 ° C. As a metal structure that excels in hardness and corrosion resistance and has excellent strength and prevents cracking, the exhaust valve rod of a diesel engine can have a long service life.

The side view of the exhaust valve rod of one embodiment of the present invention, The exhaust side of the exhaust valve rod, the enlarged side sectional view of the seat surface, Expanded side cross-sectional views (a), (b) of overlay welding of the lower side of the flaming surface and sheet surface part Enlarged side cross-sectional views (a), (b), Expanded side cross-sectional views (a), (b), (c), The expanded sectional side view (a), (b), (c) of overlay welding repair of the sheet surface part same as the above.

  The exhaust valve rod of a diesel engine or the like of the present invention uses heat-resistant steel of valve materials including SUH1, 3, 4, SUH31, Nimonic 80, 81, which are generally used as a base material of the exhaust valve rod. On the surface, an inconel high-temperature corrosion-resistant Ni-based metal that does not contain a P (phosphorus) component is deposited on the surface, and the surface layer is mainly composed of Ni 40-60% and Cr 60-40%. It is characterized in that a super-alloy high-temperature corrosion-resistant Ni-based metal is overlay welded, and the overlay metal is diluted to form overlay welding.

Table 1 Chemical composition table of exhaust valve stem

  An exhaust valve rod 1 of a marine diesel engine is formed in a mushroom shape as shown in FIG. 1, functions as a valve for exhausting exhaust gas from a piston cylinder, and is used as a base material for the exhaust valve rod 1 for a diesel engine. As a martensitic heat-resistant steel SUH1, 3, 4 or austenitic heat-resistant steel SUH31, 37, SNCrW-based, Nimonic 80, 81 Ni-based heat-resistant steel Can be used. These chemical components (%) are shown in Table 1.

  The contact surface 3 of the discharge valve rod 1 is formed by selecting and combining the most suitable welding metal materials at the present time. As shown in FIG. 2, the base surface layer has a P (phosphorus) component as shown in Table 2. Ni-base metal such as Inconel 600, 601 (INT600, 601) which does not contain high-temperature corrosion-resistant welding rods are used, and the surface layer has Ni 40-60%, Cr 60-40%, Mo0-O as shown in Table 2. Superalloys of superalloys such as SUPER ALLOY (Mitsubishi Metal MC Alloy) and SUPER ALLOY FM72 (SPECIAL METALS Welding Products Company FM72), etc. High-temperature corrosion-resistant welding rods made of high-temperature Ni-base metals are used for overlay welding, and they have excellent resistance to high-temperature corrosion resistance and resistance to sulfur attack and vanadium attack. You can maintain long life of the exhaust valve stem, such as diesel engine, allowing significantly extended maintenance intervals.

Table 2 Chemical composition table of high-temperature corrosion-resistant welding rods for Ni-based metals

  Further, as shown in FIG. 2, high temperature resistance of Ni-based metals such as Inconel 600 and 601 which do not contain P (phosphorus) component as shown in Table 2 on the seat surface 4 of the exhaust valve rod 1 as shown in Table 2 above. Using a corrosion-resistant welding rod, overlay welding is performed on the surface layer using a Ni-based special metal such as UD520 (SPECIAL METALS Welding Products Company) that is resistant to high temperatures and high hardness corrosion resistance as shown in Table 2. It has a high temperature-high hardness, corrosion resistance, and durability, and can maintain the long life of exhaust valve rods of low-speed diesel engines that use crude heavy oil as fuel, greatly increasing maintenance intervals. It can be extended to.

  The exhaust valve stem 1 includes: 1) a material that can be used to evaluate the effects of actual use; 2) a material that can be economically matched; 3) the valve seat has high hardness and high corrosion resistance; 4 ) For the flaming surface, it is necessary to select a material that is resistant to sulfur attack, vanadium attack, and high pressure and high temperature resistance. At present, it is impossible to achieve such a condition with one kind of material, and the exhaust valve rod 1 is prepared as described above so as to supplement each other with a plurality of kinds of materials. For this purpose, a welding technique was adopted in which two or three types of thin weld metals were stacked and diluted.

  The weld overlay on the contact surface 3 and the seat surface 4 of the exhaust valve rod 1 is preheated at a preheating temperature of 200 to 300 ° C. determined by strict heat input management and an experiment using a welding technique, and temperature between passes is controlled. The above-described deposit metal required for overlay welding is coated, and after overlay welding, it is subjected to volumeification treatment at 830 to 880 ° C, and precipitation treatment is performed at 620 to 680 ° C. As a metal structure that has excellent corrosion resistance and can prevent cracking, the exhaust valve rod 1 of the diesel engine can have a long life.

  Further, an exhaust valve using heat-resistant steel, which is a valve material of SUH1, 3, 4, SUH31, 37, SNCrW series, Nimonic 80, 81, which is generally used as a base material for exhaust valve rods of diesel engines, etc. As shown in Table 3, stainless steel heat-resistant steel metal such as SUS309, 310, and 316 is overlay welded to the flaming surface 3 of the flaming surface 3 as shown in Table 3, and P ( Superconducting welding of Inconel 600 and 601 Ni-based metal with high temperature and corrosion resistance, which does not contain phosphorus component, and overlaying the surface layer with Ni 40-60% and Cr 60-40% as the main components as described above The super-alloy FM72 superalloy can be repaired by overlay welding the high-temperature corrosion-resistant Ni-base metal and diluting and depositing these overlay metals as described above. Therefore, it is possible to extend the service life by welding repair of the flaming surface 3 damaged by the use of the exhaust valve rod 1 of the diesel engine as described above.

Table 3 Chemical composition table of stainless steel heat-resistant steel metal welding rod

  Further, exhaust using heat resistant steels of SUH1, 3, 4, SUH31, 37, SNCrW series, Nimonic 80, 81 Ni-based heat resistant steel, which is generally used as a base material for exhaust valve rod 2 of a diesel engine. The valve stem 2 is formed by overlay welding stainless steel heat-resistant steel such as SUS309, 310, 316 or the like to the base surface layer of the seat surface 4 as shown in Table 3 above, and P to the intermediate surface layer as described above. Inconel 600 and 601 high-temperature corrosion-resistant Ni-base metal that does not contain (phosphorus) component is welded, and UD520 high-temperature high-hardness corrosion-resistant Ni-base special metal is coated on the surface layer as described above. It is possible to repair by overlay welding and diluting and depositing these overlay metals as described above. Therefore, the seat surface 4 damaged by the use of the exhaust valve rod 1 of the diesel engine as described above can be repaired by welding to extend the service life.

  When the base metal of the exhaust valve stem 1 is Fe-based, A1 is contained in the intermetallic compound in the deposited eutectic of the deposited metal, and it is possible to make a brittle compound with Fe of the exhaust valve stem base material. Therefore, it is necessary to cut the edge with Inconel Ni as an intermediate weld metal material as described above. The Ni-based metals of Inconel 600 and 601 do not contain a P (phosphorus) component, and are excellent in crack resistance during welding of a weld metal superalloy and can be preferably used. In addition, the thing which does not contain the component of S (sulfur) is also preferable. Further, as described above, Ni 40-60%, Cr 60-40%, and Mo0-remaining amount of the superalloy high-temperature corrosion-resistant Ni-based metal are preferable, but Ni 40-60% based on the spirit of the present invention other than Mo is preferable. Further, a material containing 60 to 40% of Cr as a main component and some other metals can also be used.

Table 4 is an example summarizing these weld metal dilution and hardness test combinations.
Table 4 Weld metal dilution and hardness test combination table

  FIG. 1 and subsequent figures show an embodiment of the present invention. The exhaust valve rod 1 of the diesel engine of the present invention uses the heat resistant steel of the valve material of SUH31 generally used for the base material of the exhaust valve rod body 2, and the Inconel 600 is formed on the lower ground layer of the flaming surface 3. Overlay welding is performed by submerged arc welding using a welding rod, and superposition welding is performed by submerged arc welding using a SUPER ALLOY (Mitsubishi Metals MC alloy) welding rod on the surface layer, and the lower ground layer of seat surface 4 The welding rod of Inconel 600 is used for overlay welding by submerged arc welding, and the surface layer is used for welding welding by submerged arc welding using the welding rod of UD520. It was superposed and diluted by submerged arc welding and welded.

  In the build-up welding, for example, the exhaust valve rod 1 is mounted and fixed on a predetermined turntable, and the lower ground layer of the contact surface 3 and the seat surface 4 as shown in FIGS. 3 (a) and 3 (b). And preheating with a gas burner while rotating at a preheating temperature of 250 to 300 ° C. obtained by an experiment by a welding method corresponding to the chemical composition and welding rod of the exhaust valve stem body 2 of the exhaust valve stem 1. . First, on the flaming surface 3, as shown in FIG. 3A, overlay welding of a required lower ground layer is performed with a welding rod Inconel 600 / Inco flux. Next, as shown in FIG. 3 (b), the sheet surface 4 was subjected to overlay welding of a required lower ground layer with a welding rod Inconel 600 / Inco flux.

  And about the said flaming surface 3 and the sheet | seat surface 4, about the flaming surface 3, it carries out the required preheating similarly, respectively, as shown in FIG. 4 (a), (b). Overlay overlay welding of the surface layer with the welding rod MC alloy / Inco flux, and then overlay overlay welding of the surface layer with the welding rod UD520 / Inco flux is performed on the sheet surface 4 and then 4 hours at 870 ° C. Next, after completion of a solidification process, a precipitation hardening process of 8 Hr at 670 ° C. was performed, and a finished process was performed.

  In this way, heat resistant steel, which is a valve material generally used for the base material of the exhaust valve rod 1 of a diesel engine, is used, and there is no P (phosphorus) in the base surface layer on the flaming surface 3 and resistance to welding during welding. A superalloy Ni-base metal welding rod that uses SUPER ALLOY (Mitsubishi Metals MC Alloy) Sulfur attack resistance and vanadium attack resistance resistance to high temperature and corrosion resistance. The valve material can be manufactured inexpensively and economically, and the contact surface 3 is heated at a high temperature by a combination of an Inconel welding rod and a superalloy Ni-based metal welding rod. It has excellent corrosion resistance and can maintain the long life of exhaust valve rods of low-speed diesel engines that use crude heavy oil as a fuel, greatly extend the maintenance interval and contribute to the reduction of customer expenses. Then, by diluting these two types of overlay welding with submerged arc welding and performing volumeification treatment and precipitation hardening treatment, it is possible to achieve hardness and strength, and a surface layer superimposed on the ground surface layer. The occurrence of cracks can be prevented, and the durability can be improved as described above, making it closer to maintenance-free.

  Further, the seat surface 4 of the exhaust valve rod is also a combination of an Inconel welding rod containing no P (phosphorus) component and a UD520 high-temperature high-hardness corrosion-resistant superalloy Ni-based special metal welding rod. Hardness of the seat surface of the rod can be maintained up to a high temperature range, it is excellent in high temperature-high hardness and corrosion resistance, and can maintain the long-term life of exhaust valve rods such as low speed diesel engines fueled with crude heavy oil The maintenance interval can be greatly extended, and the customer's expenses can be reduced. Then, by diluting these two types of overlay welding with submerged arc welding and performing volumeification treatment and precipitation hardening treatment, it is possible to achieve hardness and strength and to improve durability as described above. Can be made maintenance-free.

  Further, as shown in FIGS. 5A, 5B, and 5C, in repairing the damage of the exhaust valve rod 1 of the diesel engine as described above, the damaged portion of the flaming surface 3 is inspected. Prior to the above-described overlay welding process, the base surface layer is subjected to the required groove processing and overlay welding is performed with the welding rod SUS309 / bond flux S1, and the intermediate surface layer is also subjected to the required opening. Prior processing and overlay welding with the above-mentioned welding rod Inconel 600 / Inco flux, the surface layer is also subjected to the necessary groove processing and overlay welding with the above-mentioned SUPER ALLOY MC alloy / Inco flux. These three types of overlay welding were diluted, submerged, and precipitation hardened by submerged arc welding, and repaired by welding. By repairing by overlay welding as described above, it is possible to weld and repair the damaged flaming surface 3 due to the use of the exhaust valve rod 1 of the diesel engine as described above, thereby extending the service life for a long time. .

  Further, as shown in FIGS. 6A, 6B, and 6C, similarly, in repairing damage to the exhaust valve rod 1 of the diesel engine, the damaged portion of the seat surface 4 is inspected and required. Before the above-described overlay welding process, overlay welding is performed on the sheet surface 4 using a welding rod / bond flux S1 of SUS309 on the base surface layer, and Inconel 600 / Inco flux is applied on the intermediate surface layer. Welding welding of UD520 / Inco flux on its surface layer, and welding repair of these three types of overlaying welding by submerged arc welding, dilution, solidification treatment and precipitation hardening treatment . By repairing by overlay welding as described above, the damaged seat surface 4 due to use of the exhaust valve rod 1 of the diesel engine can be repaired by welding to extend the service life for a long time.

  The exhaust valve rod 1 of a marine diesel engine can be preheated to a required preheating temperature and coated with a weld metal for overlay welding repair, and the member is not affected by air. It is preferable that heat treatment is performed as described above in a vacuum furnace of millibar) or a vacuum furnace in an inert gas atmosphere, a heat treatment furnace such as an electric furnace or a gas furnace, and damage due to oxides or carbide formation can be prevented.

  In the embodiment, the base material of the exhaust valve rod 1 of the diesel engine has been described with respect to SUH31. However, austenitic SUH37, SNCrW, etc., martensitic SUH1, 3, 4, etc. valve material heat resistant steel, Nimonic 81 Ni-base heat-resistant steel can be selected and carried out in the same manner. Inconel 601 Ni-base metal, Inconel filler metal 72 superalloy Ni-base metal, SUS310, 316 welding for heat-resistant steel Rods, MIG welding, TIG welding, and the like can also be implemented based on the spirit of the present invention, and appropriate combinations of these and modifications thereof can be implemented.

  The present invention can be used for exhaust valve rods of all internal combustion engines, such as marine diesel engines, gasoline engines, and other aircraft, locomotives, etc., which perform reciprocating motion with pistons.

      DESCRIPTION OF SYMBOLS 1 ... Exhaust valve rod 2 ... Exhaust valve rod body 3 ... Fire surface 4 ... Seat surface

JP-A-5-22475

Furthermore, the soluble conjugated treated with 830 880 ° C. after overlay welding, is to provide an exhaust valve stem, such as a diesel engine, characterized in that the precipitation hardening treatment at 620 to 680 ° C..

The present invention, as in claim 6, and soluble conjugated treated with 830 880 ° C. after overlay welding, 620-680 by the precipitation hardening treatment at ° C., above the overlay weld part hot - As a metal structure with high hardness, excellent corrosion resistance, and excellent crack prevention, it can extend the life of exhaust valve rods of diesel engines.

The weld overlay on the contact surface 3 and the seat surface 4 of the exhaust valve rod 1 is preheated at a preheating temperature of 200 to 300 ° C. determined by strict heat input management and an experiment using a welding technique, and temperature between passes is controlled. covering the required deposited metal build-up welding as described above, was treated soluble conjugated at 830 880 ° C. after overlay welding of Sawahimen 3, 620-680 treated precipitating at ° C., the overlay weld part described above As a metal structure that is excellent in high temperature-high hardness and corrosion resistance and can prevent cracking, the exhaust valve rod 1 of the diesel engine can have a long life.

And about the said flaming surface 3 and the sheet | seat surface 4, about the flaming surface 3, it carries out the required preheating similarly, respectively, as shown in FIG. 4 (a), (b). Overlay overlay welding of the surface layer with the welding rod MC alloy / Inco flux, and then overlay overlay welding of the surface layer with the welding rod UD520 / Inco flux is performed on the sheet surface 4 and then 4 hours at 870 ° C. was dissolved embodied process, then the completed processing after performing the precipitation hardening treatment 8Hr at 670 ° C., and the product through the required inspection.

In this way, heat resistant steel, which is a valve material generally used for the base material of the exhaust valve rod 1 of a diesel engine, is used, and there is no P (phosphorus) in the base surface layer on the flaming surface 3 and resistance to welding during welding. A superalloy Ni-base metal welding rod that uses SUPER ALLOY (Mitsubishi Metals MC Alloy) Sulfur attack resistance and vanadium attack resistance resistance to high temperature and corrosion resistance. The valve material can be manufactured inexpensively and economically, and the contact surface 3 is heated at a high temperature by a combination of an Inconel welding rod and a superalloy Ni-based metal welding rod. It has excellent corrosion resistance and can maintain the long life of exhaust valve rods of low-speed diesel engines that use crude heavy oil as a fuel, greatly extend the maintenance interval and contribute to the reduction of customer expenses. Surface is then diluted such two types of overlay welding by submerged arc welding, by solvent embodied process, the precipitation hardening process, it is possible to include a hardness and strength, superimposed on the lower ground layer It is possible to prevent the occurrence of cracks in the layer, and the durability can be improved as described above, which can be made maintenance-free.

Further, the seat surface 4 of the exhaust valve rod is also a combination of an Inconel welding rod containing no P (phosphorus) component and a UD520 high-temperature high-hardness corrosion-resistant superalloy Ni-based special metal welding rod. Hardness of the seat surface of the rod can be maintained up to a high temperature range, it is excellent in high temperature-high hardness and corrosion resistance, and can maintain the long-term life of exhaust valve rods such as low speed diesel engines fueled with crude heavy oil The maintenance interval can be greatly extended, and the customer's expenses can be reduced. Then, it was diluted such two types of overlay welding by submerged arc welding, soluble conjugated processed by the precipitation hardening process, it is possible to include a hardness and strength, the durability, as described above It can be raised and brought closer to maintenance-free.

Further, as shown in FIGS. 5A, 5B, and 5C, in repairing the damage of the exhaust valve rod 1 of the diesel engine as described above, the damaged portion of the flaming surface 3 is inspected. Prior to the above-described overlay welding process, the base surface layer is subjected to the required groove processing and overlay welding is performed with the welding rod SUS309 / bond flux S1, and the intermediate surface layer is also subjected to the required opening. Prior processing and overlay welding with the above-mentioned welding rod Inconel 600 / Inco flux, the surface layer is also subjected to the necessary groove processing and overlay welding with the above-mentioned SUPER ALLOY MC alloy / Inco flux. 3 dilutions types of overlay welding by submerged arc welding, welded repaired by soluble conjugated treatment, the precipitation hardening process. By repairing by overlay welding as described above, it is possible to weld and repair the damaged flaming surface 3 due to the use of the exhaust valve rod 1 of the diesel engine as described above, thereby extending the service life for a long time. .

Further, as shown in FIGS. 6A, 6B, and 6C, similarly, in repairing damage to the exhaust valve rod 1 of the diesel engine, the damaged portion of the seat surface 4 is inspected and required. Before the above-described overlay welding process, overlay welding is performed on the sheet surface 4 using a welding rod / bond flux S1 of SUS309 on the base surface layer, and Inconel 600 / Inco flux is applied on the intermediate surface layer. and the overlay welding, and the overlay welding of UD520 / Inco flux on the surface layer, diluting these three overlay welding by submerged arc welding, welding repair and dissolved embodied process, the precipitation hardening treatment did. By repairing by overlay welding as described above, the damaged seat surface 4 due to use of the exhaust valve rod 1 of the diesel engine can be repaired by welding to extend the service life for a long time.

  The present invention relates to exhaust valve rods for various diesel engines of ships.

  Conventionally, various kinds of martensitic heat-resistant steels SUH1, 3, 4 or austenitic heat-resistant steels SUH31, 37, SNCrW are used as exhaust valve rods for various diesel engines and gasoline engines of ships. Coal stellite or Ni-based metal plating such as colmonoy is used on the sheet surface.

  The exhaust valve rod is the most important and expensive component in diesel engines and gasoline engines, and the weight of the exhaust valve rod in the shipowner's economy is quite large. Thus, attempts have been made to extend the life of the exhaust valve rod so far.

  In the past, in the actual machine test that increased the high temperature strength of the sintered stellite valve seat, the seat surface was healthy and without any indentation even after 16,000 hours, and the exhaust valve stem was used for the seat surface. If the high-temperature strength is higher than a certain value, it was considered that the maintenance time and the life of the valve can be made longer than the current situation.

  In addition, from 20 years ago, as disclosed in Japanese Patent Laid-Open No. 5-22475, an exhaust valve rod made of Ni-based heat-resistant steel Nimonic (Nimonic (registered trademark) 80A) material has been used. This valve material has better heat and corrosion resistance than the above metal material, has a long service life, and is currently stable in quality in large diesel engines.

  In addition, most of the high temperature corrosion of the valve umbrella contact surface common to the exhaust valve stem is first carburized by the high temperature and high pressure exhaust gas, which reacts with the chrome of the chemical component of the exhaust valve body and reacts with chrome carbide. It was thought that it was formed at the grain boundaries and caused carburizing pitting.

  Around 1984, when repairing the exhaust valve seat of the forged product Nimonic80A, the welding material of the same kind (Nimonic80A) was used, and the surface of the weld was peened and the surface of the welded part was peened to increase the hardness. By using age-hardening heat treatment and increasing the hardness at high temperature, the service life was considerably extended.

  On the other hand, the temperature of the exhaust valve umbrella surface during engine operation is recorded at 600 ° C. or higher and 100 ° C. or higher at 100% load of the 880BHP / cyl engine. Considering the recent fuel oil properties, in addition to the above phenomenon, it is necessary to provide an exhaust valve rod excellent in high-temperature corrosion resistance such as sulfur attack resistance and vanadium attack resistance.

  Thus, in order to achieve a long life of the exhaust valve rod, 1) the metal of the exhaust valve seat is a material that can obtain high hardness at high temperatures, and 2) the metal on the flaming surface side is in a high-temperature high-pressure corrosive atmosphere 3) Exhaust valve base metal that is based on metallic Fe is an intermetallic compound in the precipitated eutectic of the metals that constitute 1) and 2). If Fe is included, a brittle compound may not be formed if Fe-based, so the edges must be cut with Ni.

  Further, marine low-speed diesel engines use poor fuel, and parts around the combustion chamber are exposed to harsh conditions. Among them, exhaust valve stems are most severe. The maintenance of the exhaust valve rod must stop the engine and release the exhaust valve rod, and this maintenance interval is currently estimated at 10,000 hours. However, engine manufacturers and customers are planning to cut costs with the goal of over 50, OOOHr in the near future.

  Further, in the past, when looking at troubles in the exhaust valve rod and solutions, most of them are troubles caused by gas blow-out from the seat surface and high-temperature corrosion of the contact surface.

  The cause of this is that there are many aspects resulting from the use of poor heavy oil, and the most effective countermeasures are to increase the high-temperature hardness of the seat surface material, and the exhaust valve stem with a material that stops high-temperature corrosion on the contact surface. Is to make.

  However, since the above materials are very expensive, when manufacturing an exhaust valve stem, a conventionally used class of material is coated with a long-life type high-quality material to comprehensively have a long life. The challenge was to make an inexpensive exhaust valve rod and make it maintenance-free.

The present invention has been made in view of the above points, and in order to solve the above-described problems, the present invention is an exhaust valve rod for a diesel engine or the like, which is generally used for a base material of the exhaust valve rod. 4, heat resistant steel of valve material including SUH31, Nimonic 80, 81 is used, and the high temperature corrosion resistance of Inconel (Inconel (registered trademark) is the same below) which does not contain P (phosphorus) component on its flaming surface. Overlay welding of Ni-base metal, and overlay welding of high-temperature corrosion-resistant Ni-base metal of superalloy mainly composed of Ni 40-60% and Cr 60-40% on the top surface of the overlay welding, to provide an exhaust valve stem, such as a diesel engine, characterized in that the solvent adhesion formed by diluting the Sheng metal.

In addition, an Inconel high-temperature corrosion-resistant Ni-based metal that does not contain P (phosphorus) component is overlay welded to the exhaust valve rod seat surface, and the high-temperature high-hardness corrosion resistance of UD520 is applied to the top surface of the overlay welding . An object of the present invention is to provide an exhaust valve rod for a diesel engine or the like, characterized by depositing and welding a Ni-based special metal and diluting these overlay metals.

Further, an exhaust valve rod using heat-resistant steel of valve materials including SUH1, 3, 4, SUH31, Nimonic 80, 81 generally used as a base material for exhaust valve rods of diesel engines, etc. stainless refractory steel metal was overlay welding, the buildup welding were top surface P Ni based metal high temperature corrosion-resistant Inconel containing no components (phosphorus) the overlay welding including S US309,310,316 to Furthermore, overlay welding is performed on the high-temperature corrosion-resistant Ni-base metal of a superalloy mainly composed of Ni 40 to 60% and Cr 60 to 40% on the overlay welded surface , and these overlay metals are diluted. An object of the present invention is to provide an exhaust valve rod for a diesel engine or the like, characterized by being welded and repaired.

Furthermore, SUH1,3,4 commonly used for the base material of the exhaust valve stem of the diesel engine, SUH31, a exhaust valve rod using heat-resisting steel valve material comprising Naimonikku 80 and 81, to the seat surface stainless refractory steel metal containing S US309,310,316 by overlay welding, P Ni-based metal high temperature corrosion-resistant Inconel containing no components (phosphorus) to deposit welding on the overlay welding to upper surface Further , a diesel engine characterized by overlay welding a high temperature, high hardness, corrosion resistant Ni-based special metal of UD520 on the top surface of the overlay welding, and diluting and welding these overlay metals to repair them. Is to provide exhaust valve rods and so on.

  Still another object of the present invention is to provide an exhaust valve rod for a diesel engine or the like, wherein the weld overlay is formed by dilution by a submerged arc welding method.

  Still another object of the present invention is to provide an exhaust valve rod for a diesel engine or the like, which is formed by solution treatment at 830 to 880 ° C. after overlay welding and precipitation hardening at 620 to 680 ° C.

The present invention is an exhaust valve rod of a diesel engine or the like as claimed in claim 1 of the utility model, and is generally used for a base material of the exhaust valve rod. SUH1, 3, 4, SUH31, Nimonic 80 , 81 is used, and heat-resistant steel of the valve material including 81 is used, and the high temperature corrosion-resistant Ni-base metal of Inconel that does not contain the P (phosphorus) component is overlay welded to the contact surface , Exhaust valve by overlay welding of high temperature corrosion resistant Ni base metal of superalloy mainly composed of Ni 40-60%, Cr 60-40%, and diluting these overlay metals to form overlay welding Uses heat resistant steel of valve material such as SUH1, 3, 4, 37, Nimonic 80, 81, etc., which is generally used as a base material for rods, and there is no P (phosphorus) on the flaming surface, and resistance to cracking during welding Inconel's excellent high temperature resistance and high temperature corrosion resistance Ni-base metal and Exhaust from low-speed diesel engines using crude heavy oil as fuel, with a combination of superalloy Ni-based metals with excellent resistance to high temperature and corrosion resistance such as Rufer Attack and Banadium Attack. The long life of the valve stem can be expected to be maintained, the maintenance interval can be greatly extended, and the customer's expenses can be reduced.

Further, according to the present invention, as described in claim 2, on the seat surface of the exhaust valve rod, an inconel high-temperature corrosion-resistant Ni-based metal that does not contain P (phosphorus) component is overlay welded, and the overlay weld is performed. By overlay welding a high temperature, high hardness, corrosion resistant Ni-based special metal of UD520 on the top surface , and diluting these overlay metals to form a weld, there was no P (phosphorus) as described above. Combining Inconel's high-temperature corrosion-resistant Ni-based metal welding rod with excellent crack resistance, and high-temperature, high-hardness corrosion-resistant UD520 Ni-based special metal, the exhaust valve rod has a high surface hardness. High hardness can be maintained up to the range, high temperature-high hardness and excellent corrosion resistance, can maintain the long life of exhaust valve rods of low speed diesel engines etc. fueled with crude heavy oil, and can greatly extend the maintenance interval , Helping to reduce customer expenses You can.

Further, the present invention uses heat resistant steel of valve material including SUH1, 3, 4, SUH31, Nimonic 80, 81, which is generally used as a base material for exhaust valve rods of diesel engines, etc., as in claim 3. It is an exhaust valve rod, and a stainless steel heat resistant steel metal containing SUS309, 310, 316 is overlay welded to its flaming surface , and the resistance of Inconel that does not contain P (phosphorus) component on the overlay welded upper surface. Overlay welding high temperature corrosion resistant Ni-base metal, and overlay welding the super-high temperature corrosion resistance Ni base metal of superalloy mainly composed of Ni 40-60% and Cr 60-40% In addition, by diluting and repairing these overlay metals, welding and repairing the flaming surface damaged by the use of the exhaust valve rod of a diesel engine, the service life is extended as described above. be able to.

Further, according to the present invention, as in claim 4, exhaust using heat resistant steel of a valve material including SUH1, 3, 4, SUH31, Nimonic 80, 81 generally used for a base material of an exhaust valve rod of a diesel engine. High temperature corrosion resistance of Inconel, which is a valve stem and is made by overlay welding stainless steel for heat resistance including SUS309, 310, 316 on the seat surface , and does not contain P (phosphorus) component on the top surface Laying welding is performed on the upper surface of the welded Ni-base metal, and the high-temperature, high-hardness and corrosion-resistant Ni-base special metal of UD520 is welded on top of the weld-welded surface. As a result of the repair, the seat surface damaged by the use of the exhaust valve rod of the diesel engine can be repaired by welding to extend the service life as described above.

  Further, according to the present invention, as described in claim 5, by forming the build-up welding by diluting by the submerged arc welding method, the above-described build-up welded portion is excellent in strength and prevents cracking. It is possible to extend the service life by overlay welding the contact surface damaged by the use of the exhaust valve rod of the diesel engine.

  Further, according to the present invention, as described in claim 6, after the overlay welding, solution treatment is performed at 830 to 880 ° C. and precipitation hardening is performed at 620 to 680 ° C. As a metal structure that excels in hardness and corrosion resistance and has excellent strength and prevents cracking, the exhaust valve rod of a diesel engine can have a long service life.

The side view of the exhaust valve rod of one embodiment of the present invention, The exhaust side of the exhaust valve rod, the enlarged side sectional view of the seat surface, Expanded side cross-sectional views (a), (b) of overlay welding of the lower side of the flaming surface and sheet surface part Enlarged side cross-sectional views (a), (b), Expanded side cross-sectional views (a), (b), (c), The expanded sectional side view (a), (b), (c) of overlay welding repair of the sheet surface part same as the above.

The exhaust valve rod of a diesel engine or the like of the present invention uses heat-resistant steel of valve materials including SUH1, 3, 4, SUH31, Nimonic 80, 81, which are generally used as a base material of the exhaust valve rod. Superconducting of Inconel that does not contain P (phosphorus) component on the surface, and overlay welding the Ni-based metal with high temperature and corrosion resistance, and the upper surface of the welding is Ni40-60% and Cr60-40% The high-temperature corrosion-resistant Ni-based metal is overlay welded, and the overlay metal is diluted to form overlay welding.

Table 1 Chemical composition table of exhaust valve stem

  An exhaust valve rod 1 of a marine diesel engine is formed in a mushroom shape as shown in FIG. 1, functions as a valve for exhausting exhaust gas from a piston cylinder, and is used as a base material for the exhaust valve rod 1 for a diesel engine. As a martensitic heat-resistant steel SUH1, 3, 4 or austenitic heat-resistant steel SUH31, 37, SNCrW-based, Nimonic 80, 81 Ni-based heat-resistant steel Can be used. These chemical components (%) are shown in Table 1.

Sawahi surface 3 of the exhaust valve stem 1 is a combination selected welding metal material most appropriate at the moment, the Sawahi surface 3 which corresponds to the lower ground layer as shown in FIG. 2 as in Table 2 Using a high-temperature corrosion-resistant welding rod of Ni-base metal such as Inconel 600, 601 (INT600, 601) that does not contain P (phosphorus) component , the surface layer of the base layer is the surface layer corresponding to the top surface welded As shown in Fig. 2, SU40 ALLOY (Mitsubishi Metal MC Alloy) and SUPER ALLOY FM72 (Inconel Filler Metal 72 (SPECIAL METALS Welding Products Company FM72)) of Ni 40-60%, Cr 60-40%, Mo0 remaining amount Overlay welding using high-temperature corrosion-resistant welding rods of Ni-based metals of superalloys mainly composed of Ni 40-60% and Cr 60-40%, excellent in high-temperature corrosion resistance of sulfur attack and vanadium attack resistance Resistance Shall have the sex, the inferior heavy oil can maintain long life of the exhaust valve stem, such as low-speed diesel engine is a fuel, allowing significantly extended maintenance intervals.

Table 2 Chemical composition table of high-temperature corrosion-resistant welding rods for Ni-based metals

Further, as shown in FIG. 2, high temperature corrosion resistance of Ni-based metals such as Inconel 600 and 601 which do not contain P (phosphorus) component in the base layer corresponding to the seat surface 4 of the exhaust valve rod 1 as shown in Table 2 above. High temperature, high hardness, corrosion resistance welding of Ni-based special metals such as UD520 (SPECIAL METALS Welding Products Company) as shown in Table 2 on the surface layer corresponding to the top surface of the base layer that has been welded. It is formed by overlay welding using a rod, and maintains the long-term life of exhaust valve rods such as low-speed diesel engines that use crude heavy oil as fuel, because it is durable and excellent in high temperature-high hardness and corrosion resistance The maintenance interval can be greatly extended.

  The exhaust valve stem 1 includes: 1) a material that can be used to evaluate the effects of actual use; 2) a material that can be economically matched; 3) the valve seat has high hardness and high corrosion resistance; 4 ) For the flaming surface, it is necessary to select a material that is resistant to sulfur attack, vanadium attack, and high pressure and high temperature resistance. At present, it is impossible to achieve such a condition with one kind of material, and the exhaust valve rod 1 is prepared as described above so as to supplement each other with a plurality of kinds of materials. For this purpose, a welding technique was adopted in which two or three types of thin weld metals were stacked and diluted.

  The weld overlay on the contact surface 3 and the seat surface 4 of the exhaust valve rod 1 is preheated at a preheating temperature of 200 to 300 ° C. determined by strict heat input management and an experiment using a welding technique, and temperature between passes is controlled. The above-mentioned required weld metal for overlay welding is coated, and after overlay welding, solution treatment is performed at 830 to 880 ° C. and precipitation treatment is performed at 620 to 680 ° C. As a metal structure that has excellent corrosion resistance and can prevent cracking, the exhaust valve rod 1 of the diesel engine can have a long life.

Further, an exhaust valve using heat-resistant steel, which is a valve material of SUH1, 3, 4, SUH31, 37, SNCrW series, Nimonic 80, 81, which is generally used as a base material for exhaust valve rods of diesel engines, etc. a rod 1, a steel metal stainless heat such SUS309,310,316 as shown in Table 3 and overlay welding to the underlying surface layer which corresponds to the Sawahi surface 3, and overlay welding of the lower ground layer top As described above, the Inconel 600 and 601 high-temperature corrosion-resistant Ni-based metal that does not contain the P (phosphorus) component is overlay welded to the intermediate surface layer corresponding to the above, and the above-described surface layer corresponding to the top surface of the overlay weld is applied to the surface layer. As shown above, superposition welding of high-temperature corrosion-resistant Ni-base metals of superalloys of SUPER ALLOY and SUPER ALLOY FM72, whose main components are Ni 40-60% and Cr 60-40%, is carried out as described above. Dilute the weld formation Can be repaired. Therefore, it is possible to extend the service life by welding repair of the flaming surface 3 damaged by the use of the exhaust valve rod 1 of the diesel engine as described above.

Table 3 Chemical composition table of stainless steel heat-resistant steel metal welding rod

Further, exhaust using heat resistant steels of SUH1, 3, 4, SUH31, 37, SNCrW series, Nimonic 80, 81 Ni-based heat resistant steel, which is generally used as a base material for exhaust valve rod 2 of a diesel engine. As shown in the above Table 3, stainless steel heat-resistant steel metal such as SUS309, 310, and 316 is overlay welded to the base surface layer corresponding to the seat surface 4 of the valve stem 2 and overlay welded to the base surface layer. As described above, the Inconel 600 and 601 high-temperature corrosion-resistant Ni-based metal that does not contain the P (phosphorus) component is overlay welded to the intermediate surface layer that hits the top surface, and the surface layer that corresponds to the top surface subjected to the build-up weld As described above, it is possible to build up and weld a ND520 high-temperature, high-hardness, corrosion-resistant Ni-based special metal and dilute and build-up these built-up metals as described above. Therefore, the seat surface 4 damaged by the use of the exhaust valve rod 1 of the diesel engine as described above can be repaired by welding to extend the service life.

  When the base metal of the exhaust valve stem 1 is Fe-based, A1 is contained in the intermetallic compound in the deposited eutectic of the deposited metal, and it is possible to make a brittle compound with Fe of the exhaust valve stem base material. Therefore, it is necessary to cut the edge with Inconel Ni as an intermediate weld metal material as described above. The Ni-based metals of Inconel 600 and 601 do not contain a P (phosphorus) component, and are excellent in crack resistance during welding of a weld metal superalloy and can be preferably used. In addition, the thing which does not contain the component of S (sulfur) is also preferable. Further, as described above, Ni 40-60%, Cr 60-40%, and Mo0-remaining amount of the superalloy high-temperature corrosion-resistant Ni-based metal are preferable, but Ni 40-60% based on the spirit of the present invention other than Mo is preferable. Further, a material containing 60 to 40% of Cr as a main component and some other metals can also be used.

Table 4 is an example summarizing these weld metal dilution and hardness test combinations.
Table 4 Weld metal dilution and hardness test combination table

FIG. 1 and subsequent figures show an embodiment of the present invention. Exhaust valve stem 1 of the diesel engine of the present invention uses a heat resistant steels of the valve material SUH31 commonly used for the base material of the exhaust valve stem body 2, a welding rod of Inconel 600 on the Sawahi surface 3 use by overlay welding by submerged arc welding, and overlaying welding in submerged arc welding using a welding rod of SUPER aLLOY (Mitsubishi Metal MC alloy) to the overlay welding was top, Inconel 600 on the seat surface 4 Welding welding is performed by submerged arc welding using the welding rod of the above, and welding welding is performed by submerging arc welding using the welding rod of UD520 on the top surface of the welding welding, and these two kinds of overlaying welding metal are used. It was superposed and diluted by submerged arc welding and welded.

In welding the above cladding, for example the exhaust valve rod 1 and fixed by mounting a predetermined turntable, FIG. 3 (a), GMA processed into Sawahi surface 3 and the seat surface 4 as shown in (b) Then, preheat with a gas burner while rotating at a preheating temperature of 250 to 300 ° C. obtained by an experiment by a welding method corresponding to the chemical components of the exhaust valve rod body 2 of the exhaust valve rod 1 and the welding rod. Then, first, the Sawahi surface 3, to the required overlay welding with welding rod Inconel 600 / Inco flux as shown in FIG. 3 (a). Next, as shown in FIG. 3 (b), the sheet surface 4 was subjected to the required overlay welding with a welding rod Inconel 600 / Inco flux.

Then, with respect to the flaming surface 3 and the sheet surface 4, as shown in FIGS. 4 (a) and 4 (b), the upper surface of each overlay welding is processed, and the necessary preheating is performed in the same manner. On the fire surface 3, overlay welding is performed with the welding rod MC alloy / Inco flux , and then on the seat surface 4, overlay welding is performed with the welding rod UD520 / Inco flux , and then the solution is heated to 870 ° C. for 4 hours. Then, after carrying out 8Hr precipitation hardening treatment at 670 ° C., it was finished and processed through a required inspection to obtain a product.

In this way, heat resistant steel, which is a commonly used valve material, is used for the base material of the exhaust valve rod 1 of the diesel engine, and its flaming surface 3 has no P (phosphorus) and has excellent crack resistance during welding. Superconducting Ni-base metal welding rods with super high resistance to high temperature corrosion resistance such as SUPER ALLOY (Mitsubishi Metals MC Alloy) anti-sulfur attack and vanadium attack are used. In addition, the valve material can be manufactured at low cost and economically by overlay welding, and the contact surface 3 can be made high temperature-corrosion resistant by combining Inconel welding rod and superalloy Ni-based metal welding rod. It can maintain the long life of exhaust valve rods such as low speed diesel engines that use crude heavy oil as fuel, can greatly extend the maintenance interval, and can contribute to the reduction of customer expenses. Then, was diluted such two types of overlay welding by submerged arc welding, by solution treatment, the precipitation hardening process, it is possible to include a hardness and strength, heavy in Sawahimen 3 topping It is possible to prevent cracking of the surface layer that hits the upper surface, and the durability can be improved as described above, which can be made maintenance-free.

  Further, the seat surface 4 of the exhaust valve rod is also a combination of an Inconel welding rod containing no P (phosphorus) component and a UD520 high-temperature high-hardness corrosion-resistant superalloy Ni-based special metal welding rod. Hardness of the seat surface of the rod can be maintained up to a high temperature range, it is excellent in high temperature-high hardness and corrosion resistance, and can maintain the long-term life of exhaust valve rods such as low speed diesel engines fueled with crude heavy oil The maintenance interval can be greatly extended, and the customer's expenses can be reduced. Then, by diluting these two types of overlay welding with submerged arc welding and subjecting them to solution treatment and precipitation hardening, it is possible to achieve hardness and strength and to improve durability as described above. Can be made maintenance-free.

Further, as shown in FIGS. 5A, 5B, and 5C, in repairing the damage of the exhaust valve rod 1 of the diesel engine as described above, the damaged portion of the flaming surface 3 is inspected. It performs the necessary processing, prior to the above-mentioned overlay welding, and overlaying welding in welding rod SUS309 / bonded flux S1 by the beveling of the Kaname Tokoro in Sawahimen 3, to the overlay welding to upper surface In addition, the above-mentioned SUPER ALLOY MC alloy / Inco was prepared by performing the necessary groove processing and overlay welding with the above-mentioned welding rod Inconel 600 / Inco flux, and further performing the necessary groove processing on the top surface of the overlay welding. Overlay welding was performed with flux, and these three types of overlaid welding were diluted, solution-treated, and precipitation-hardened by submerged arc welding to repair welding. By repairing by overlay welding as described above, it is possible to weld and repair the damaged flaming surface 3 due to the use of the exhaust valve rod 1 of the diesel engine as described above, thereby extending the service life for a long time. .

Further, as shown in FIGS. 6A, 6B, and 6C, similarly, in repairing damage to the exhaust valve rod 1 of the diesel engine, the damaged portion of the seat surface 4 is inspected and required. Before the above-described overlay welding process, the sheet surface 4 is overlay welded using the welding rod / bond flux S1 of SUS309, and the top surface of the overlay welding is inconel 600 / Inco flux meat. Weld welding, and then overlay welding of UD520 / Inco flux on the top surface of the overlay welding, and diluting, solution treatment, precipitation hardening treatment of these three kinds of overlay welding by submerged arc welding Repaired. By repairing by overlay welding as described above, the damaged seat surface 4 due to use of the exhaust valve rod 1 of the diesel engine can be repaired by welding to extend the service life for a long time.

  The exhaust valve rod 1 of a marine diesel engine can be preheated to a required preheating temperature and coated with a weld metal for overlay welding repair, and the member is not affected by air. It is preferable that heat treatment is performed as described above in a vacuum furnace of millibar) or a vacuum furnace in an inert gas atmosphere, a heat treatment furnace such as an electric furnace or a gas furnace, and damage due to oxides or carbide formation can be prevented.

In the embodiment, the base material of the exhaust valve rod 1 of the diesel engine has been described with respect to SUH31. However, austenitic SUH37, SNCrW, etc., martensitic SUH1, 3, 4, etc. valve material heat resistant steel, Nimonic 80 and 81 Ni-base heat-resistant steel can be selected and implemented in the same manner. Also, Ni-base metal of Inconel 601, Ni-base metal of superalloy of Inconel filler metal 72, SUS310, 316, etc. These welding rods, MIG welding, TIG welding, and the like can be carried out based on the gist of the present invention, and appropriate combinations thereof and variations thereof can be carried out.

  The present invention can be used for exhaust valve rods of all internal combustion engines, such as marine diesel engines, gasoline engines, and other aircraft, locomotives, etc., which perform reciprocating motion with pistons.

      DESCRIPTION OF SYMBOLS 1 ... Exhaust valve rod 2 ... Exhaust valve rod body 3 ... Fire surface 4 ... Seat surface

JP-A-5-22475

Claims (6)

Exhaust valve rods for diesel engines, etc., and heat resistant steels for valve materials including SUH1, 3, 4, SUH31, Nimonic 80, 81 (Nimonic (registered trademark)), which are generally used for the base material of exhaust valve rods use,
An inconel (registered trademark) high-temperature corrosion-resistant Ni-based metal that does not contain a P (phosphorus) component in the base surface layer is welded to the flaming surface, and Ni 40-60% is applied to the surface layer. A diesel engine or the like characterized by overlay welding a high temperature corrosion resistance Ni-base metal of a superalloy mainly composed of Cr 60 to 40% and diluting these overlay metals Exhaust valve rod.   Inconel high-temperature corrosion-resistant Ni-base metal that does not contain P (phosphorus) component in the base surface layer of the exhaust valve rod is welded, and the surface layer of UD520 is resistant to high-temperature and high-hardness corrosion resistance. The exhaust valve rod for a diesel engine or the like according to claim 1, wherein Ni-based special metal is welded and welded to form a welded metal. An exhaust valve rod using heat-resistant steel of valve materials including SUH1, 3, 4, SUH31, Nimonic 80, 81 generally used as a base material for exhaust valve rods of diesel engines,
A stainless steel for heat-resisting stainless steel containing SUS309, 310, 316 is overlay welded to its flaming surface, and Inconel's high-temperature corrosion-resistant Ni-base does not contain P (phosphorus) component in its intermediate surface layer. Overlay welding of metal, and overlay welding high temperature corrosion resistance Ni base metal of superalloy mainly composed of Ni 40-60% and Cr 60-40% on the surface layer, and diluting these overlay metals Exhaust valve rods for diesel engines, etc., characterized by being welded and repaired. An exhaust valve rod using heat-resistant steel of a valve material including SUH1, 3, 4, SUH31, Nimonic 80, 81 generally used for a base material of an exhaust valve rod of a diesel engine,
Inconel high-temperature corrosion-resistant Ni-base metal that does not contain P (phosphorus) component in the intermediate surface layer by overlay welding stainless steel heat-resisting steel metal containing SUS309, 310, 316 on the base surface. Diesel is characterized by being welded and welded with a high temperature, high hardness, corrosion resistant, Ni-based special metal on its surface layer, and the weld metal was diluted and welded to repair. Exhaust valve rod for engines, etc.   The exhaust valve rod for a diesel engine or the like according to any one of claims 1 to 4, wherein the weld overlay is formed by dilution by a submerged arc welding method.   The exhaust valve rod for a diesel engine or the like according to any one of claims 1 to 5, wherein the exhaust valve rod is subjected to volumeification treatment at 830 to 880 ° C after overlay welding and precipitation hardening at 620 to 680 ° C.

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